Decorative hardwood paneling and trim



Jan. 27, 1-970 R. A. HANN 3,491,813

DECORATIVE HARDWOOD PANELING AND TRIM Filed Aug. 15. 1968 INVENTOR.

I ROBERT A. HA/V/V BY /Z- 1% United States Patent O 3,491,813 DECORATIVE HARDWOOD PANELING AND Robert A. Hann, Black Earth, Wis., assignor to the Umted States of America as represented by the Secretary of Agriculture Filed Aug. 15, 1968, Ser. No. 752,825 Int. Cl. B27m 1/00 US. Cl. 144-320 4 Claims ABSTRACT OF THE DISCLOSURE A wood product and the process for producing the product are disclosed. A uniform internal checking is produced by drying refractory hardwoods of desired thickness in a wood press dryer at a temperature above 350 F. and a pressure below 50 p.s.i. The wood is left in the press dryer for a time suflicient to bring the mid-section of the wood to about a 6 percent mois-ure content. After removal from the press any one or all of the faces of the wood are sanded, planed, jointed, or otherwise machined to expose the internal checking that has been created.

A nonexclusive, irrevocable, royalty-free license in the invention herein described throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a wood product that is especially appealing as a paneling or trim material and a process for producing the same. The wood product is produced by a variation of the standard press drying process followed by machining of the wood.

Description of the prior art To the best of the inventors knowledge the wood product herein claimed has not been produced before. At present, there is very little or no market for the lower grades of the refractory hardwoods used in this invention.

The process used is basically a standard press drying process but has been varied to bring about new and unique results in the end product. The. standard press drying process is used to reduce the moisture content of the wood to a workable level and to preshrink it before use. In addition, press drying produces a wood product which substantially improves shrinkage and warping problems during the post fabrication period. However, press drying has not been used on refractory hardwoods before because of extreme blotchy darkening of the wood and a severe non-uniform surface checking which results in an unuseable end product. Furthermomore, it would not be obvious to those skilled in the art to use press drying on these hardwoods because of the expectation and danger that the wood would explode when the press is opened.

SUMMARY A new wood product that is especially desirable as a trim or paneling material is produced. Any of the refractory hardwoods or check-prone hardwoods can be used.

The wood is first prepared to the size and thickness desired in the end product plus allowances of -20 percent for shrinkage and approximately 1 inch which will be machined off the surface. The wood is placed in a press dryer at a temperature above 350 F. and at a pressure below 50 p.s.i. A temperature of 350 F. and a pressure of 50 p.s.i. are the respective maximum and minimum usually used in the standard press drying process.

The wood is left in the press dryer for a time sufficient to bring the moisture content to a workable level.

It is this combination of the variations above the temperature and below the pressure usually used in the standard press drying process that makes this process a new and unobvious use of press drying as applied to refractory or check-prone hardwoods. Instead of the extreme blotchy darkening of the wood that results from the use of the standard process, a word with uniform darkening ise produced. Instead of severe non-uniform surface checking of the wood, a wood with controlled, extensive and uniform internal checking is produced. In addition, the wood does not explode upon opening of the press as is frequently the case when the standard process is used.

Upon removal from the press, the surface or surfaces of the wood are sanded, planed, jointed, or otherwise machined in order to expose the internal checking that has been caused by this process. The combination of the uniform darkening and controlled checking make this end product very appealing and desirable as a decorative trim or paneling material. The wood product can be produced from the low grades of the refractory or checkprone hardwoods, for which there is presently very little market. Such a new market is especially important to the depressed areas such as Appalachia BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a perspective view of a typical piece of wood after removal from the press dryer, but before removal of any of the surface material.

FIGURE 2 is a sectional view taken through section line 22 in FIGURE 1 and shows that the checking is mostly internal.

FIGURE 3 is a perspective view, taken through section line 3-3 in FIGURE 2, of the typical piece of wood shown in FIGURE 1 after the end has been trimmed and approximately inch of material has been removed from the surface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS More specifically, white oak is sawed or sliced into typical sized pieces of wood for wall paneling or whatever other use it is desired for. The thickness of these typical pieces is determined by the thickness desired for the end use, plus an allowance of approximately 20 percent for shrinkage and an additional A inch that will be removed to expose the internal checking. The wood is then placed between heated platens with a temperature of preferably 350 to 450 F. and under a pressure of preferably 25 to 50 p.s.i. The wood is kept in the press for a time sufficient to bring the moisture content down to 6 percent at its mid-section.

The above steps are similar to a standard press drying process. However, the temperature used here is above the 350 F. maximum used in the standard process. Also, the pressure used is not the same as used in the standard process, but rather is below the 50 p.s.i. minimum that is therein used.

When the moisture content has been lowered to the desired level, the wood is removed from the press. At this stage, there is very little or no checking showing through the surfaces of the wood as shown in FIGURE 1. This is in contrast to the appearance of and effect on the refractory or check-prone hardwoods if they have been put through the standard press drying process. In the latter case, there will be severe non-uniform surface checking of the wood. There will also be extreme blotchy darkening of the wood, whereas with the present process, the wood will be darkened but the color change is uniform.

Looking now at FIGURES 1 and 3, after removal from the press, the surface 11 is planed, jointed, or otherwise machined to remove approximately inch of the surface material. The controlled, extensive and uniform internal checking is thus exposed as is shown on surface 12 of FIGURE 3. Approximately A6 inch of material is also removed from end 13 of FIGURE 1 in order to expose the checking on the end if desired as shown by end 14 of FIGURE 3. As is shown by FIGURE 2, the internal checking occurs throughout the wood.

Similarly, if it is desired, the surface 15 of FIGURE 2 opposite surface 11 can be machined so as to expose the checking on both surfaces. Whether this is done will depend on the end use to which the wood is put. It is expected that the checking need be exposed on only one surface when the wood is used for paneling. Exposure of the checking at both surfaces may be desirable where the wood is to be used for decorative trim purposes such as for a room divider.

It has been found that the same controlled internal checking and uniform darkening occurs with any checkprone hardwood, among which are red oak, post oak, hickory, elm, ash, and the white oak mentioned in the above description.

In addition to using single opening presses, the same results would also be attained with a multi opening or continuous platen press.

Having thus disclosed my invention, I claim:

1. A process for producing a decorative wood product from refractory hardwoods wherein the wood is prepared in the size and thickness desired plus shrinkage and machining allowances, then placed between heated platens of a press dryer, kept in the dryer for a time sufficient to bring the moisture content at the mid-section of the Wood to a workable level, wherein the improvement comprises using a press temperature greater than 350 F. and a pressure less than 50 p.s.i.

2. The process of claim 1 wherein the press temperature is maintained at 350 to 450 F.

3. The process of claim 1 wherein the press pressure is maintained at 25 to 50 p.s.i.

4. The process of claim 1 wherein after removal of the wood from the press dryer, approximately his inch is removed from the surface of the wood, thus exposing the controlled, extensive, and uniform internal checking in the wood.

References Cited UNITED STATES PATENTS 446,962 2/ 1891 Bryce 52-316 904,446 2/ 1908 Possons 144-322 2,724,642 2/1955 Brown 144-324 X HENRY C. SUTHERLAND, Primary Examiner PRICE C. FAW, JR, Assistant Examiner US. Cl. X.R. 

